Air Quality Assessment Using Affordable Monitoring Units – Nairobi Demonstration Project
UN Environment Assembly Adopts Resolution to strengthen UNEP’s Air Quality work June 2014 - Governments Adopt UNEA Resolution #7: Strengthening the role of the United Nations Environment Programme in promoting air quality
Air Quality Data currently available GAPS! Source: UNEP Live
Air Quality Monitors: High cost to Affordable Mt. Kenya St. Scholastica School Reference Air Quality Monitoring Station -High accuracy -High Costs ($150,000-$200,000) -High installation costs -High operation costs Affordable Air Quality Monitor -Sufficient accuracy -Affordable (~few $100-$1000) -Low installation costs -Low operation costs
Assessment through enhanced and low-cost monitoring UNEP National Air Quality Monitoring Programme Many countries and cities in world regions have limited or no air pollution data UNEP offers services to support deployment of low-cost monitoring networks and assessment of air quality Requests received from Peru, Paraguay, Costa Rica, Ro Korea, Cote D’Ivoire, Indonesia, Mongolia, Moldova, Austria UNEP has developed an affordable air quality monitoring unit Using electro-chemical sensors for gases and Optical Particle Counter for particulate matter Blue prints publically available Calibration at US EPA ongoing
Nairobi Low-Cost AQ Network , mostly schools in NASA Globe Program
Nairobi PM2.5 – scaled individually Distinct local emission features evident across Nairobi
Policy Relevance Continuous indicative monitoring helps inform policy formulations and implementation: Illustrative measurements from data generated gives a snapshot of pollution events Source attribution to determine pollution sources and hotspots SDG Reporting 11.6.2: Annual mean levels of particulate matter (PM10 and PM2.5) in cities 3.9.1: Mortality rate attributed to household and ambient air pollution Continuous data stream established with Kenyan authorities for use in policy and decision making
Policy Relevance – Illustrative measurements Time series PM2.5
Policy Relevance – Source Apportionment The Where? – Pollution sources Site 1 – Kibera Site 2 – Viwandani Site 3 – Scholastica Site 4 – UNEP HQ Site 5 – All Saints Site 6 – Alliance
Policy Relevance – Source Attribution The What? - St. Scholastica PM2.5 Daily Patterns Diurnal Pattern Monthly Averages Daily Means Traffic related source…
Policy Relevance – Intervention Study Nairobi Placemaking Week Street closures around Jeevanjee Gardens – Nov 2016
Conclusion The successful deployment has shown that: Low-cost monitoring units are able to generate data for processing, verification and visualization Data collected is sufficiently accurate to determine the state of air quality, pollution hot spots and pollution sources **Maintaining reliability of the data and increasing accuracy would require access to calibration of the network alongside reference instrumentation at one location The network can be implemented and maintained locally The units are deployable in cities with limited infrastructure and difficult operating conditions
Summary Low cost sensors viable for ‘indicative’ (<25% error) monitoring, mapping and source apportionment of urban pollution. Network intelligence and availability of reference station can increase the accuracy to make the data viable for compliance (<15% error) EU CEN/TC 264/WG 42 is working towards defining a framework for validation of low cost sensors. Few years away!! We are still learning about deployment. Still some caveats (T/RH effects) Proven success in use of low cost sensors elsewhere e.g OpenSense, SNAQ, CitiSense, Village Green, MIT Clairity Low cost sensors (particulates including Black Carbon, gas phase including Volatile Organic Compounds) continue to advance